Corrosion Resistance Mechanism in WC/FeCrNi Composites: Decoupling the Role of Spherical Versus Angular WC Morphologies
In this study, we investigated the electrochemical corrosion behavior and mechanisms of FeCrNi/WC alloys with varying contents of CTC-S (spherical WC) and CTC-A (angular WC) in a 3.5 wt.% NaCl solution, addressing the corrosion resistance requirements for stainless steel composites in marine environ...
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2025-07-01
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| author | Xiaoyi Zeng Renquan Wang Xin Tian Ying Liu |
| author_facet | Xiaoyi Zeng Renquan Wang Xin Tian Ying Liu |
| author_sort | Xiaoyi Zeng |
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| description | In this study, we investigated the electrochemical corrosion behavior and mechanisms of FeCrNi/WC alloys with varying contents of CTC-S (spherical WC) and CTC-A (angular WC) in a 3.5 wt.% NaCl solution, addressing the corrosion resistance requirements for stainless steel composites in marine environments. The electrochemical test results demonstrate that the corrosion resistance of the alloy initially increases with the CTC-A content, followed by a decrease, which is associated with the formation, stability, and rupture of the passivated film. Nyquist and Bode diagrams for electrochemical impedance spectroscopy confirm that the charge transfer resistance of the passivated film is the primary determinant of the composite’s corrosion performance. A modest increase in CTC-A contributes to the formation of a more heterogeneous second phase, providing a physical barrier and enhancing solid solution strengthening, and thus delaying the cracking and corrosion processes of the passivation film. However, excessive CTC-A content leads to significant dissolution of the alloy’s reinforcement phase and promotes decarburization, resulting in the formation of corrosion pits, craters, and cracks that compromise the passivation film and expose fresh alloy surfaces to further corrosion. When the CTC-A content is 10% and the CTC-S content is 30%, this combination results in minimal degradation in the corrosion performance (0.213 μA·cm<sup>2</sup>) while balancing the hardness and toughness of the alloy. Additionally, electrochemical evaluations reveal that incorporating angular CTC-A particles at 10 vol% effectively delays the breakdown of the passivation film by mitigating the interfacial galvanic coupling through enhancing the mechanical interlocking at the WC/FeCrNi interface. The CTC-A/CTC-S hybrid system exhibits a remarkable 62% reduction in the pitting propagation rate compared to composites reinforced solely with spherical WC, which is attributed to the preferential dissolution of angular WC protrusions that sacrificially suppress crack initiation at the phase boundaries. |
| format | Article |
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| spelling | doaj-art-0315f22a24ee47a788ebb0180ea583422025-08-20T02:47:19ZengMDPI AGMetals2075-47012025-07-0115777710.3390/met15070777Corrosion Resistance Mechanism in WC/FeCrNi Composites: Decoupling the Role of Spherical Versus Angular WC MorphologiesXiaoyi Zeng0Renquan Wang1Xin Tian2Ying Liu3Intelligent Engineering College, Chongqing Electric Power College, Chongqing 400030, ChinaSchool of Materials Science & Engineering, Sichuan University, Chengdu 610065, ChinaSchool of Materials Science & Engineering, Sichuan University, Chengdu 610065, ChinaSchool of Materials Science & Engineering, Sichuan University, Chengdu 610065, ChinaIn this study, we investigated the electrochemical corrosion behavior and mechanisms of FeCrNi/WC alloys with varying contents of CTC-S (spherical WC) and CTC-A (angular WC) in a 3.5 wt.% NaCl solution, addressing the corrosion resistance requirements for stainless steel composites in marine environments. The electrochemical test results demonstrate that the corrosion resistance of the alloy initially increases with the CTC-A content, followed by a decrease, which is associated with the formation, stability, and rupture of the passivated film. Nyquist and Bode diagrams for electrochemical impedance spectroscopy confirm that the charge transfer resistance of the passivated film is the primary determinant of the composite’s corrosion performance. A modest increase in CTC-A contributes to the formation of a more heterogeneous second phase, providing a physical barrier and enhancing solid solution strengthening, and thus delaying the cracking and corrosion processes of the passivation film. However, excessive CTC-A content leads to significant dissolution of the alloy’s reinforcement phase and promotes decarburization, resulting in the formation of corrosion pits, craters, and cracks that compromise the passivation film and expose fresh alloy surfaces to further corrosion. When the CTC-A content is 10% and the CTC-S content is 30%, this combination results in minimal degradation in the corrosion performance (0.213 μA·cm<sup>2</sup>) while balancing the hardness and toughness of the alloy. Additionally, electrochemical evaluations reveal that incorporating angular CTC-A particles at 10 vol% effectively delays the breakdown of the passivation film by mitigating the interfacial galvanic coupling through enhancing the mechanical interlocking at the WC/FeCrNi interface. The CTC-A/CTC-S hybrid system exhibits a remarkable 62% reduction in the pitting propagation rate compared to composites reinforced solely with spherical WC, which is attributed to the preferential dissolution of angular WC protrusions that sacrificially suppress crack initiation at the phase boundaries.https://www.mdpi.com/2075-4701/15/7/777spark plasma sintering (SPS)tungsten carbide-reinforced stainless steelseawater corrosionWC morphologycomposite materials |
| spellingShingle | Xiaoyi Zeng Renquan Wang Xin Tian Ying Liu Corrosion Resistance Mechanism in WC/FeCrNi Composites: Decoupling the Role of Spherical Versus Angular WC Morphologies Metals spark plasma sintering (SPS) tungsten carbide-reinforced stainless steel seawater corrosion WC morphology composite materials |
| title | Corrosion Resistance Mechanism in WC/FeCrNi Composites: Decoupling the Role of Spherical Versus Angular WC Morphologies |
| title_full | Corrosion Resistance Mechanism in WC/FeCrNi Composites: Decoupling the Role of Spherical Versus Angular WC Morphologies |
| title_fullStr | Corrosion Resistance Mechanism in WC/FeCrNi Composites: Decoupling the Role of Spherical Versus Angular WC Morphologies |
| title_full_unstemmed | Corrosion Resistance Mechanism in WC/FeCrNi Composites: Decoupling the Role of Spherical Versus Angular WC Morphologies |
| title_short | Corrosion Resistance Mechanism in WC/FeCrNi Composites: Decoupling the Role of Spherical Versus Angular WC Morphologies |
| title_sort | corrosion resistance mechanism in wc fecrni composites decoupling the role of spherical versus angular wc morphologies |
| topic | spark plasma sintering (SPS) tungsten carbide-reinforced stainless steel seawater corrosion WC morphology composite materials |
| url | https://www.mdpi.com/2075-4701/15/7/777 |
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